Network Fundamentals

Agenda

  • Basic Terms
  • OSI and TCP/IP Model
  • Protocols
  • Advanced Topics

Basic Terms

Client

MAC Address

  • 12 Character Number assigned to each Client
  • Used to address local Clients over Wire or Wireless
  • Can usually be changed manually

IP Address

  • Two Version 4 and 6
  • 32 or 128 Bit
  • Used to address Clients
  • Can be changed within the local Network
  • Mostly fixed for public IP address

Switch

Router

OSI and TCP/IP Model

OSI Model

TCP/IP Model

OSI vs TCP/IP Model

Protocols

Address Resolution Protocol (ARP)

  • Maps MAC to IP Address
  • Local Cache of Mapping
  • Request for missing Items
  • Data Link or Network Access Layer

Transmission Control Protocol (TCP)

  • Protocol for delivering Messages
  • Reliable, Ordered and Error Checked
  • Transport Layer

User Data Protocol (UDP)

  • Protocol for delivering Messages
  • Shoot and Forget, Fast
  • Transport Layer

File Transfer Protocol (FTP)

  • Used to transfer Files
  • Application Layer
  • Port 21

Secure Shell (SSH)

  • Securely access Computer over insecure Network
  • Application Layer
  • Port 22

Dynamic Host Configuration Protocol (DHCP)

  • Automate Network Configuration of Service
  • Network and Data Link or Network and Network Access Layer
  • Port 67

Domain Name System (DNS)

  • Map IP Address to Hostname
  • Application Layer
  • Port 53

Hypertext Transfer Protocol (HTTP)

  • Used to transfer and interact with Media
  • Application Layer
  • Port 80

Routers and Firewalls

Routing

  • How to reach other Network

Rules

  • IPs
  • Ports
  • Protocol
  • Dangerous Traffic

VPN

  • Secure Connection over insecure Network
  • Encryption
  • Hide private Information
  • Access internal Resources